With the diversification of notebook computers, detachable notebook computers, e.g., Thinkpad Helix or Waltz notebook computers, become more and more popular. In a detachable notebook computer, contents are displayed on a tablet computer which is connected with a keyboard in a detachable manner. That is, a user can attach the keyboard to, or detach it from, the tablet computer. When the keyboard is attached to the tablet computer, they get close to each other and establish a connection with each other via wireless chips, e.g., WaveConnex wireless chips, for data communication. However, when the tablet computer is rotated around the keyboard, the relative position between the tablet computer and the keyboard varies continuously, resulting in a continuous variation of the distance between the wireless chip at the tablet computer and the wireless chip at the keyboard. Hence, the radio frequency (RF) power transmitted between the two wireless chips has to be set to an RF power required for the maximum distance between them, so as to ensure the transmission quality for any arbitrary relative position between the tablet computer and the keyboard. However, the transmission power of the chips is not adaptive to use scenarios, which leads to excessive power consumption of the wireless chips and reduces the battery life of the device.